Calculate sleep cycles and optimal bedtimes.
Recommended wake times are calculated in 90-minute sleep cycles backward from a target bedtime or wake time.
To wake at 7:00 AM, aim to fall asleep at 11:30 PM for five full cycles (7.5 hours).
A cycle of sleep stages lasting about 90 minutes. Waking at the end of a cycle often feels easier than mid-cycle.
Most adults need 7–9 hours, or about 4–6 full cycles per night.
No. Sleep needs vary. Consult a provider for persistent sleep problems.
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